Method for outputting traffic information in a motor vehicle

ABSTRACT

The invention relates to a method for outputting traffic information in a motor vehicle. In order to present the driver with traffic information in such a way that he can adapt his driving behaviour and/or his selection of a route for his journey to the respective current traffic situation in time, there is a provision that traffic messages are stored together with the respective position of the route section to which they relate. The positions of the traffic messages are then compared with the respective position of a motor vehicle in which the traffic information is to be output in order to detect the distances between the respective position of the traffic messages and the position of this motor vehicle. The traffic messages are then output sorted according to distances, starting with the smallest distance.

[0001] The invention relates to a method for outputting trafficinformation in a motor vehicle.

[0002] It has already been known for some time to output trafficmessages via radio transmitters so that the drivers of motor vehiclescan listen to these traffic messages using a radio receiver in thevehicle. The individual radio transmitters supply essentially onlytraffic messages which relate to the relevant transmission area.Furthermore, the traffic messages are usually sorted in such a way thatthey are output according to the importance of the respective roads inquestion. Traffic messages relating to motorways are therefore usuallybroadcast before such messages relating to trunk roads and towns.

[0003] If, as is the case in conurbation areas, there are very largenumbers of messages, the driver of a vehicle has to pay carefulattention to the traffic messages as they are received, in order todetermine whether there are traffic messages which are relevant to him.This can be extremely disruptive and distract the driver from thecurrent events on the road. On the other hand, it is frequently the casehere that the driver pays careful attention to the individual trafficmessages, but at the decisive moment is disrupted by the current eventson the road which, for reasons of safety, have priority for the driver'sattention, with the result that he in fact fails to hear the trafficmessage which is of interest to him.

[0004] In addition to this traffic information system which uses publicand private radio transmitters, further traffic information systemswhich permit a user, that is to say for example a driver of a motorvehicle, to request traffic information on a specific basis are alreadyknown.

[0005] In such a known traffic information system, the driver of a motorvehicle can communicate the geographic area for which he wishes to havetraffic information to a terminal installed in the motor vehicle, beforehe begins a journey. To do this he has to enter appropriate informationinto the terminal, for instance the fact that the driver in futurewishes to move within a town or intends, for example, to aim for a moredistant destination on an overland route or a motorway. In the formercase, only traffic information which relates to a circular region with apredetermined radius around the motor vehicle is displayed orcommunicated to the driver. The driver can also determine the magnitudeof the radius. In contrast, in the latter case, the driver is onlyprovided with traffic information which applies to a predefined regionaround the motor vehicle and to that region in which the motor vehicleis moving in the direction of the destination. In the second case, theregion for which relevant traffic information is obtained is, as itwere, in the form of a keyhole. Here too, radii and distances can befreely selected by the driver before he begins his journey, or can bepredefined by the system.

[0006] Although in this traffic information system the number of trafficmessages is reduced by the specific geographic limitation of the regionfor which traffic messages are output, the user who is interested intraffic information has to listen to all the traffic messages in orderto determine whether there are traffic messages which are relevant tohim.

[0007] On this basis, the invention is based on the object of makingavailable a method for outputting traffic information in a motorvehicle, which makes it possible to output the traffic messages on aspecific basis in such a way that the interested user is informed asquickly as possible of the traffic situation which is important for him.

[0008] This object is achieved by means of the method according to claim1. Advantageous refinements of the invention are described in thesubclaims.

[0009] According to the invention, traffic information is thereforestored together with the respective position of the route section orpoint to which it relates. Before the traffic information is output, thepositions of the traffic messages are then compared with the respectiveposition of the motor vehicle in which the traffic messages are to beoutput, in order to determine the distances between the respectivepositions in the traffic messages and the position of this motorvehicle. The traffic messages are subsequently sorted according todistances and output starting with the smallest distance. The firsttraffic message which is announced or displayed to the driver using themethod according to the invention is therefore the traffic message whichis closest to the current position of the motor vehicle. Depending onthe type of traffic message, the driver can thus decide immediately towhat extent the announced traffic situation or the announced routestatus directly influences his route planning, so that, if appropriate,he can still in good time select an alternative route instead of theplanned route.

[0010] According to a first exemplary embodiment of the invention, thereis provision for the sorted traffic messages to be transmitted to amotor vehicle. Here, the traffic messages are therefore already sortedby the service provider, that is to say the operator of the trafficinformation system, so that the terminal in the motor vehicle foroutputting the traffic information can be of extremely simple design.

[0011] However, in another advantageous development of the invention,there is provision for the traffic messages to be transmitted to a motorvehicle, sorted there and stored, the traffic messages which aretransmitted to a motor vehicle being continuously updated atpredefinable time intervals.

[0012] This permits the driver of a motor vehicle to have up-to-datetraffic information announced or displayed to him at any time, thistraffic information being output as a function of the current location.

[0013] In an advantageous development of the invention there isprovision for only traffic messages which relate to a selected area tobe stored and are subsequently output in the motor vehicle. This allowsthe number of traffic messages to be stored to be significantly reduced,with the result that, on the one hand, the memory requirements in theterminal are kept relatively small and, on the other hand, the sortingtime before outputting can be reduced.

[0014] Although it is possible for the selection of the trafficinformation which is to be transmitted to be made by the serviceprovider in accordance with the area which is relevant for therespective vehicle, this selection can also be carried out in the motorvehicle by means of an appropriate filter routine, directly afterreception of the traffic information.

[0015] If a driver generally only drives within a specific area with hismotor vehicle, for example as a taxi driver or a supplier, it isexpedient if the selected area surrounds the position of the motorvehicle in an essentially circular shape. However, if a route is plannedfor a journey to a distant destination, for example on an overloadroute, it is expedient if the selected area can be defined with respectto the particular current position of the motor vehicle as a function ofa planned route for a journey, surrounding it in a corridor-likefashion.

[0016] In order to prevent the traffic messages which are not relevantto the driver being announced or displayed to him, according to anadvantageous development of the invention there is provision for eachtraffic message to be transmitted together with an item of updatinginformation which describes the anticipated duration of the generalrelevance of the respective traffic information, for the average vehiclespeed to be detected, logically linked to the distances assigned to thetraffic messages and compared with the updating information in order todetect the specific relevance of the respective traffic message, and foronly traffic messages which have already been assessed relevant to therespective vehicle in terms of timing to be output.

[0017] This makes it possible to prevent, for example, a report oftraffic congestion being announced to the driver of a vehicle if saidannouncement relates to a route section of his planned route but islikely to be long out of date when he reaches this route section. If itis therefore, for example, possible to expect that congestion which is,for example, 200 km away on the planned route will have cleared, forexample, in an hour the driver of a vehicle which is travelling 100 km/hon average does not need to have this congestion announced to himbecause the vehicle will not reach this section of the route until twohours later, that is to say when the traffic message no longer applies.

[0018] In this context, it is particularly expedient if the updatinginformation of the respective traffic message contains the transmissiontime, the anticipated duration and the detection time of the reportedevent.

[0019] In one advantageous refinement of the invention there isprovision for first the direction of travel of the motor vehicle to bedetected, for the direction of the motor vehicle with respect to theparticular position of the traffic message to be detected and to becompared with the direction of travel, and for the traffic messages tobe output sorted according to directions. In this way it is possible toensure that two or more traffic messages which relate to traffic eventswhich are at equal distances from the current position of the motorvehicle can be output sorted once more according to their instantaneousdirection-dependent relevance for the driver. A traffic event whichoccurs near to a putative route is not output in such a case until afterthe announcement or display of the traffic event which has occurred at aplace directly in front of the vehicle.

[0020] Here, it is also possible to determine by means of the directionin which the position of the traffic message, that is to say thelocation of the traffic event which is to be reported lies viewed fromthe instantaneous position of the vehicle whether the traffic messagerelates to the respective road in the direction of travel or thecarriageway or carriageways in the opposite direction in order to avoidtraffic messages relating to the opposite direction being announced ordisplayed.

[0021] One advantageous refinement to the invention is characterized bythe fact that a directional factor is formed for each traffic messagefrom the direction of the motor vehicle with respect to the particularposition of the traffic message and the direction of travel, whichfactor is combined with the distance assigned to the respective trafficmessage to form a local relevance factor which is taken into accountduring the outputting of the traffic messages, a traffic message beingpreferably output only if its local relevance factor is higher than apredefinable threshold value.

[0022] Another advantageous refinement of the invention is characterizedin that the position of the motor vehicle is determined as a Geocodeusing a satellite-supported position-determining system, in particularwith the GPS (Global Positioning System), and in that the positions ofthe traffic messages are also provided as Geocodes, with the result thatthe distances can be determined without further conversion calculations.By using Geocodes, it is possible to determine particularly easily boththe distances between the vehicle and route sections affected by thetraffic messages, the direction of travel and the directions of thevehicle with respect to the route distances.

[0023] The invention is explained in more detail below, by way ofexample, with reference to the drawing, in which:

[0024]FIG. 1 shows a simplified, diagrammatic view of a user unit foruse as a terminal in a traffic information system,

[0025]FIG. 2 shows a flowchart of a filter routine which is used in themethod according to the invention,

[0026]FIG. 3 shows a flowchart of a first exemplary embodiment of themethod according to the invention, and

[0027]FIG. 4 shows a flowchart of another exemplary embodiment of themethod according to the invention.

[0028] Components and method steps which correspond to one another areprovided with the same reference symbols in the different figures of thedrawing.

[0029] As is shown in FIG. 1, a user unit which can be used as aterminal in a traffic information service system has a centralprocessing and control unit 10 which is embodied, for example, as amicroprocessor μP and to which a mobile phone 11 is connected astelecommunication unit for communication with a control centre of a roador traffic information service system, and to which, for example, a GPSmodule 12 is connected as a position-finding module of asatellite-supported position-determining system. To operate the userunit, an input unit 13 is provided which may be, for example, a voiceinput unit, a complete alphanumeric keyboard, a keypad, such as is usedalso in telephones, in particular in mobile phones, or in the simplestcase a lock-down rotary actuator. It is also possible, instead of aseparate input unit 13, to use the keypad of the mobile phone 11 or avoice input unit which is provided in the mobile phone 11.

[0030] In order to display system acknowledgements while the user unitis being operated, and in particular while the communication with thecontrol centre of the information service system is being prepared, andin order to display information which is transmitted by the informationservice system to the user unit and information which is stored there, adisplay unit 14 and/or a voice output unit 15 are expediently connectedto the central processing and control unit 10. The display unit 14 maybe a screen embodied, for example, as a liquid crystal display here.

[0031] A storage unit 16 is used for the temporary or permanent storageof traffic information and other data.

[0032] The method according to the invention is explained in more detailbelow, by way of example, with reference to the flowcharts illustratedin the drawing. When the user unit is operating, the user, that is tosay in particular the driver of a motor vehicle is provided not onlywith a multiplicity of further operating functions (not illustrated inmore detail) by means of a “traffic information” menu item but also hasthe possibility of requesting current traffic information and having itdisplayed and/or announced depending on the features of the terminal.

[0033] Depending on the way in which the traffic information servicesystem is configured, the user has the possibility, by means of the userunit, of transmitting in a suitable dialogue a traffic informationrequest together with the instantaneous motor vehicle position, whichhas been determined by the GPS module 12, to the service provider, thatis to say to the control centre of the information service system. Atthe service-provider end, the traffic messages which are stored togetherwith the respective position of the route section or route point, thatis to say together with the location at which a traffic event which isto be reported is located, are sorted as a function of distance, in thatthe positions of the traffic messages are initially compared with therespective position of the motor vehicle, in order to determine thedistances from them. As soon as the sorting process has been terminated,the traffic information with the traffic messages which are storedaccording to distances can then be transmitted by the service providerto the user unit and output there in a suitable way.

[0034] However, it is preferable if only the traffic messages togetherwith the respective position of the route section to which they relateare transmitted by the control centre of the information service systemin response to a traffic information request by a user.

[0035] In order to keep the number of traffic messages which are to bestored and output later as small as possible, after traffic informationis received in step S10 and the traffic messages are buffered in stepS11 a filter routine shown in FIG. 2 is initially used to read thetraffic messages individually in step S12 in order to determine in stepS13 whether or not the position of the traffic message, that is to saythe position of the route section to which the traffic message relates,lies in an area which can be determined in advance by the user. If therelevant route section does not lie in the predetermined area, theroutine returns to step S12 in order to read the next traffic message,after checking in step S15 whether all the buffered traffic messageshave been read.

[0036] However, if the traffic message which is read in step S12 lies inthe area, the traffic message is stored in step S14. In step S15, it isthen checked whether all the traffic messages have been read. If this isthe case, the filter routine is terminated. Otherwise, the routinecontinues reading traffic messages in step S12 until all the trafficmessages have been read.

[0037] The area which is selected for the selection of the trafficmessages which are of interest for the user is either an essentiallycircular area whose radius is expediently predefined by the system ifthe user does not input an appropriate value for it. Fordestination-oriented journeys, in particular for overland journeys, itis expedient if a keyhole-like area is defined which comprises anessentially circular section with a relatively small radius around theinstantaneous position of the vehicle and a conical area lying in thedirection of the destination on both sides of the presumed route.

[0038] If the user is also provided with a navigation system in his userunit and if there is route planning to the desired destination, the areaof interest can also be selected in a corridor-like fashion along theroute, in which case the width of the corridor can either be freelyselected by the driver or can expediently be defined by the system.

[0039] As soon as all the traffic messages relating to the selected areahave been stored using the filter routine, the individual trafficmessages are output in accordance with the output routine illustrated inFIG. 3.

[0040] For this purpose, firstly the current position of the vehicle isdetermined in step S20 before the traffic messages are announced ordisplayed. As soon as a traffic message has subsequently been read instep S21, the distance between the position of the vehicle and theposition of the route section which is affected by the traffic messageis subsequently calculated in step S22. Then, in the simplest case, instep S23 the traffic message is stored together with the calculateddistance. Then, in step S24 it is checked whether all the stored trafficmessages have been read, and the routine is continued in step S21 untilthe distance from the route section for each traffic message has beencalculated. After the traffic messages have been sorted, in step S25, asa function of the distances assigned to them, in step S26 the trafficmessages are then output starting with the smallest distance.

[0041] So that, in this process, the individual traffic events, forexample congestion and obstructions, and route information, such as roadclosures, diversions and road conditions due to the weather, areannounced or displayed to the driver not only in the order in which theuser is confronted with them but also to present the user with only thetraffic messages which are actually relevant to him, it is possible, inthe routine illustrated in FIG. 3, for the specific relevance of thetraffic message to be determined in step S221, after the distancecalculation in step S22.

[0042] For this purpose, it is calculated, for example, from thedistance determined in step S22 and an average vehicle speed, when theuser will reach with his vehicle the route section which is affected bythe traffic message. This time is compared with an item of updatinginformation which is added to each traffic message and from which thepredicted end of the traffic problem which is to be reported can bedetermined. This predicted end of the traffic problem can be specifiedrelatively precisely, for example in the case of road closures orobstructions as a result of roadworks. In the case of obstructions as aresult of traffic accidents, the end can often also be estimated bytaking into account the time of the accident and the severity of theaccident.

[0043] By comparing the time at which the user is predicted to reach,with his vehicle, the corresponding route section with the end time ofthe obstruction, it is possible to determine the specific relevance ofthe traffic message for the respective user. In step S222, it is thenchecked, using the specific relevance determined, whether or not thespecific traffic message is relevant, and whether or not it should bestored, together with the distance, in step S23. In the latter case, theroutine returns to step S21 in order to read the next traffic messageafter it has been checked in step S24 whether all the buffered trafficmessages have already been read.

[0044] In another exemplary embodiment of the method according to theinvention for outputting traffic information, firstly not only thevehicle position but also the direction of travel are firstly determinedin step S20′ as shown in FIG. 4, in that, for example, a direction oftravel vector, referred for short below as direction of travel, iscalculated from two or more successive vehicle positions. Subsequently,in step S21, the traffic message is respectively read in order todetermine, in step S22′, not only the distance between the route sectionand the current position of the vehicle but also the direction withrespect to this route section. In step S33, a direction factor is thendetermined from the direction of travel and the direction of the routesection in order to calculate a local relevance, in step S34, from thedistance and the direction factor of each traffic message. Here, it isexpediently also taken into account whether the traffic event on whichthe traffic message is based is significant for the current direction oftravel or for the opposite direction of travel.

[0045] If, for example, a traffic event is located at a route sectionwhich lies ahead in the direction of travel, the angle between thedirection of travel and the direction of the route section is 0° and thetraffic message is given the local relevance 1 if it does not relate tothe opposite direction. If a traffic event is located on a route sectionwhich lies to the side of the direction of travel, the angle between thedirection of travel and the direction of route section differs from 0and the local relevance is calculated from the direction factor and thedistance. If the angle is relatively small, for example 5° or 10°, thetraffic message is assigned a relatively high relevance, which ishowever less than 1. Here, given the same direction factor, the trafficevent which lies further away is, for example, given the higherrelevance because the probability of a deviation from the instantaneousdirection of travel increases as the distance between the position ofthe traffic message and the instantaneous position of the vehicleincreases. If the route section is virtually at a right angle to thedirection of travel, or is even located behind the current position ofthe vehicle, in the case of a destination-oriented journey therespective traffic message is designated as being irrelevant.

[0046] The local relevance, which may, for example, be a value between 0and 1 or even, in binary representation, an integer between 0 and 3 or 0and 7, depending on the number of bits used, is then assigned to thetraffic message so that in step S35 it is possible to check whether thetraffic message is relevant, that is to say whether or not the localrelevance exceeds a predefined threshold of value. If the trafficmessage is considered to be relevant, it is subsequently stored in stepS23′ together with the distance and the local relevance. The thresholdvalue for the local relevance can either be defined by the user himselfor expediently by the system. If the user is, for example, driving in atown where he frequently changes his direction of travel, the thresholdvalue for the local relevance can be set, for example, to 0 in order tooutput all the traffic messages independently of the direction, butsorted according to distance and preferably also according to localrelevance. If the user is on a destination-oriented journey with hisvehicle, he can enter a relatively high threshold value so that trafficevents occurring near to his intended route are suppressed, like puttingblinkers on the system.

[0047] If a traffic message is considered as not being relevant in stepS35, the routine returns directly to step S21 in order to read the nexttraffic message, after it has been checked in step S24 whether all thebuffered traffic messages have already been read.

[0048] In step S24, it is then checked whether all the traffic messageshave been read, so that they are then sorted according to distance instep S25′. In step S26′, the traffic messages are then output startingwith the smallest distance, taking into account the local relevancefactor.

[0049] Here, for example, all the traffic messages of a distance rangeare announced or displayed depending on their relevance. It is alsopossible that first only the traffic messages with the respectivehighest relevance are output sorted according to distances, so that thetraffic messages with lower relevance are then also displayed orannounced sorted according to distance.

[0050] Furthermore, it is finally possible that, in addition to thedetermination of the local relevance in steps S33, S34 and S35, thechronological relevance, as has been determined and checked in stepsS221 and S222, is taken into account before and after the localrelevance is defined, so that the user of the traffic information systemis intentionally presented only with the traffic messages which areimportant to him in order to support him in selecting his route in anoptimum way, without distracting him unnecessarily from the events onthe road, as do, for example, traffic announcements by radiotransmitters.

1. Method for outputting traffic information in a motor vehicle, inwhich traffic messages are stored together with the respective positionof the route section or point to which they relate, the positions of thetraffic messages are compared with the respective position of the motorvehicle in which the traffic information is to be output in order todetermine the distances between the respective positions in the trafficmessages and the position of this motor vehicle, and the trafficmessages are output sorted according to distances, starting with thesmallest distance.
 2. Method according to claim 1, characterized in thatthe sorted traffic messages are transmitted to a motor vehicle. 3.Method according to claim 1, characterized in that the traffic messagesare transmitted to a motor vehicle, sorted there and stored.
 4. Methodaccording to claim 3, characterized in that the traffic messages whichare transmitted to a motor vehicle are continuously updated atpredefinable time intervals.
 5. Method according to one of claims 1 to4, characterized in that only traffic messages which relate to aselected area are stored and are subsequently output in the motorvehicle.
 6. Method according to claim 5, characterized in that theselected area surrounds the position of the motor vehicle in anessentially circular shape.
 7. Method according to claim 5,characterized in that the selected area can be defined with respect tothe particular current position of the motor vehicle as a function of aplanned route for a journey, surrounding it in a corridor-like fashion.8. Method according to one of the preceding claims, characterized inthat each traffic message is transmitted together with an item ofupdating information which describes the anticipated duration of thegeneral relevance of the respective traffic message, the average vehiclespeed is detected, logically linked to the distances assigned to thetraffic messages and compared with the updating information in order todetect the specific relevance of the respective traffic message, andonly traffic messages which have been assessed relevant to therespective vehicle in terms of timing are output.
 9. Method according toclaim 8, characterized in that the updating information of therespective traffic message contains the transmission time, theanticipated duration and the detection time of the reported event. 10.Method according to one of the preceding claims, characterized in thatfirst the direction of travel of the motor vehicle is detected, thedirection of the motor vehicle with respect to the particular positionof the traffic message is detected and is compared with the direction oftravel, and the traffic messages are output sorted according todirections.
 11. Method according to claim 10, characterized in that adirectional factor is formed for each traffic message from the directionof the motor vehicle with respect to the particular position of thetraffic message and the direction of travel, which factor is combinedwith the distance assigned to the respective traffic message to form alocal relevance factor which is taken into account during the outputtingof the traffic messages.
 12. Method according to claim 11, characterizedin that a traffic message is output only if its local relevance factoris higher than a predefinable threshold value.
 13. Method according toone of the preceding claims, characterized in that the position of themotor vehicle is detected as a Geocode using a satellite-supportedposition-determining system, in particular with the GPS (GlobalPositioning System), and in that the positions of the traffic messagesare also provided as Geocodes, with the result that the distances can bedetermined without further conversion calculations.